CCDIK, FABRIK, and TwoBoneIK all seem to be broken in their own peculiar ways, and I've been pulling my hair out trying to get this basic IK setup working.
I've got a super simple humanoid rig (I'm talking so simple it doesn't even have hands or feet) and I want to be able to rotate the body while keeping the legs grounded.
I've got it setup properly to the best of my knowledge and the only one that gives barely usable results is CCDIK, and even then, applying joint constraints breaks it!
If anyone has any kind of experience with Godot animation, please take a look at my minimal repro project! Maybe there's some kind of basic mistake I'm making!
Here's the minimal repro project with source .blend file for the character: IKIssue.zip